Today's selection of science news. Links are normally to press releases on EurekAlert (at the bottom end I may also add a couple of newspaper stories). I include quotes from the summary in italics in cases where the title alone doesn't reveal what the story is about. My own thoughts appear without italics if I have any.
Journey to the center of the Earth
In an effort to investigate conditions found at the Earth's molten outer core, researchers successfully determined the density of liquid iron and sound propagation speed through it at extremely high pressures. They achieved this with use of a highly specialized diamond anvil which compresses samples, and sophisticated X-ray measurements. Their findings confirm the molten outer core is less dense than liquid iron and also put values on the discrepancy.
Human handling stresses young monarch butterflies
People handle monarch butterflies. A lot. Every year thousands of monarch butterflies are caught, tagged and released during their fall migration by citizen scientists helping to track their movements. And thousands of caterpillars are reared by hand or used in classroom demonstrations and outreach events. These activities can provide valuable scientific data and educational benefits for the people participating in them. But how do the monarchs themselves feel about being handled by humans?
Logging threatening endangered caribou
Cutting down forests means we're also cutting down woodland caribou, says a pioneering study by University of Guelph ecologists showing that logging in Ontario's extensive boreal stands threatens populations of the elusive but iconic herbivore.
Credit: Dr. Tal Avgar
New COVID-19 test quickly and accurately detects viral RNA
Unusually clear skies drove record loss of Greenland ice in 2019
Milk pioneers: East African herders consumed milk 5,000 years ago
Little scientists: Children prefer storybooks that explain why and how things happen
From the news media:
How Cuba deals with Covid-19